This invention relates generally to mattress foundation structures and more particularly to a box spring assembly of a type which utilizes non-coil springs. Box spring assemblies of this general type have been known since 1964, the first such spring assembly being disclosed in U.S. Pat. No. 3,286,281. Subsequently issued patents disclosing the same general type of box spring assembly are: U.S. Pat. Nos. 3,487,480; 3,506,987; 3,574,240; 3,574,241; 3,665,529; 3,680,157; 3,755,833; 3,824,639; 3,852,838; 4,060,862; 4,120,058; 4,131,961; 4,195,376; 4,218,790; 4,238,861; 4,251,892; 4,253,208; 4,339,834; 4,371,152; 4,398,705; 4,470,584; 4,452,438; 4,739,977; 4,779,292; 4,779,293; 4,805,883; 4,861,002; 4,867,424; 4,891,853; 4,907,785; 4,921,228; and 4,932,535.
Box spring assemblies of the general type shown in the above list of patents, all of which are owned by the assignee of this application, are advantageous with respect to the conventional box spring assemblies using coil springs because they provide a desired stiffer foundation for the mattress and contain a reduced amount of wire. These box spring assemblies are also advantageous from the standpoints of prolonged service life, ease of assembly, and cost of manufacture.
Additional box spring assemblies of this general type are shown in U.S. Pat. Nos. 3,546,723; 3,596,299; 3,722,013; 3,825,960; 3,833,948; 3,835,485; 3,869,740; 3,990,121; and 4,000,531.
It is a principal object of this invention to provide an improved support foundation in a box spring assembly, particularly peripheral support. This is achieved by constructing the box spring assembly with crosswires that include integral sinuous end springs which, like the rest of the assembly components, are made of spring wire to provide added support and stiffness.
It is a further object of this invention to combine the various box spring components, the cross wire, intermediate springs, and sinuous and springs, into a single entity to lower the cost of manufacturing and make it easier to assemble.